1. Technical Field
The present invention relates to an actuator device equipped with a vibration plate provided on a substrate and with a piezoelectric element formed on the vibration plate. The invention also relates to a liquid-jet head and a liquid-jet apparatus both of which employ the actuator device mentioned above.
2. Related Art
A type of actuator device in which displacement of a vibration plate is caused by drive of a piezoelectric element is mounted on, for example, a head that jets a liquid (liquid-jet head, for short). A well-known example of the liquid-jet head is an ink-jet recording head in which actuator devices are provided on a passage-forming substrate where pressure-generating chambers communicating respectively with nozzle orifices are formed. When the actuator devices are driven, the ink-jet head ejects ink droplets. Put another way, the vibration plate forms a part of each pressure-generating chamber in the ink-jet recording head and is deformed by driving the corresponding piezoelectric element. When the vibration plate deforms, the ink in the pressure-generating chamber is pressurized, and ink droplets are ejected through the corresponding nozzle orifice. A type of actuator device that can be mounted on the ink-jet recording head of the above-mentioned kind is disclosed in, for example, JP-A-2000-094681. In the actuator device, a piezoelectric layer made of, for example, a thin film of PZT is evenly formed on the entire surface of the vibration plate by a film-forming method, and then the piezoelectric layer is cut into shapes, each of which corresponds to each one of pressure-generating chambers by a lithography method. The piezoelectric elements thus formed are independent of one another and correspond to pressure-generating chambers, respectively.